In general, a circuit breaker operates to engage and disengage a selected branch electrical circuit from an electrical power supply. The circuit breaker provides current interruption thereby providing protection to the electrical circuit from continuous over-current conditions and/or high-current transients due, for example. Such circuit breakers operate by separating internal electrical contacts contained within a housing of the circuit breaker.
In some embodiments, the circuit breakers include a thermal-magnetic trip unit wherein the contact arms blow apart from the stationary contacts due to magnetic forces or as a result of thermal heating of a bimetal element. In such thermal-magnetic circuit breakers, an accessory pocket may be provided that includes a magnetic trip bar that rotates in response to a short circuit that trips the circuit breaker and disconnects the electrical contacts. Certain thermal-magnetic circuit breakers may include a short circuit indicating accessory module in the accessory pocket. Furthermore, certain thermal-magnetic circuit breakers may include an internal trip switch that is activated by rotation of the trip bar to send an electrical signal to a location indicating the circuit breaker has been tripped. The short circuit indicating accessory module may mechanically and visually indicate that a short circuit trip has occurred by either sounding an alarm or providing a visual indicator.
However, such thermal-magnetic circuit breakers including short circuit indicating accessory modules may be deficient in some respects. Thus, improved short circuit indicating accessory module and assemblies including them are desired.